Pneumatic rollers for earth working machines



March 20, 1962 w. E. GRACE 3,025,775

PNEUMATIC ROLLERS FOR EARTH WORKING MACHINES Filed June 23, 1958 3 Sheets-Sheet 1 INVENTOR. WILLIAM E. GRACE March 20, 1962 w. E. GRACE PNEUMATIC ROLLERS FOR EARTH WORKING MACHINES Filed June 23, 1958 3 Sheets-Sheet 2 ATTORNEY E C A R G E M m L w W March 20, 1962 w. E. GRACE PNEUMATIC ROLLERS FOR EARTH WORKING MACHINES Filed June 23, 1958 5 Sheets-Sheet 3 INVENTOR. W l LUAM E. GRACE United States Patent Ofiice 3,025,775 Patented Mar. 20, 1962 3,025,775 PNEUMATIC ROLLERS FGR EARTH WORKING MACHINES William E. Grace, 8239 Forest Hills Blvd, Dallas, Tex. Filed June 23, 1958, Ser. No. 743,701 1 Claim. (CI. 94-50) This invention relates generally to earth-working machinery, and more particularly has reference to an earth compaction roller structure of the pneumatic type.

Heretofore, in some known constructions, the roller wheels have been disposed on rocker beams in side-byside relation, that is, the several wheels of a group or series are transversely spaced, over the full or substantially the full width of the roller frame or body. The wheels are generally disposed within a wheel-receiving recess, which recess may be of arcuate formation with a side wall in close proximity to the peripheries of the wheels.

It has been conventional practice to oscillate the wheels in pairs, in a circular path, and this has considerable disadvantage, inasmuch as the axes of rotation of the wheels travel in arcuate paths about the pivot axes of the beams, and as the wheels are moved bodily upwardly and downwardly in an arcuate path in respect to the body, they are uncontrolled in their movements, resulting in uneven compaction.

It is proposed, in view of the difiiculties which have been noted above, to provide a generally improved pneumatic roller construction, wherein each wheel will be separately mounted upon its own vertically swinging beam, thereby producing a controlled vertical movement of the rollers necessary for even compaction.

Another object is to so mount the Wheels that the compacting load will be equalized, by the provision of a separate hydraulic cylinder associated with each wheel suspension, the several cylinders being interposed between the several wheel supporting beams and the body, so that each beam has its own, individual load equalizing means, the invention having the further desirable characteristic wherein all the cylinders are connected to a common reservoir.

In accordance with the invention, the hydraulic system can be varied, as for example a valve may be so placed in the system that the wheels may oscillate in pairs, or individually, or as a complete group that includes all the wheels.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings, and to the app nded claim in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

FIG. 1 is a fragmentary side elevational view showing the rear end portion of a rolling machine of pneumatic type, a portion of the body of said machine being broken away.

FIG. 2 is a horizontal section substantially on line 2-2 of FIG. 1.

FIG. 3 is an enlarged, transverse sectional view through one of the beams, substantially on line 33 of FIG. 1.

FIG. 4 is an enlarged, transverse sectional view through one of the beams substantially on line 44 of FIG. 1, showing the mounting of the wheel thereon.

FIG. 5 is an enlarged, fragmentary perspective view of one of the wheel support beams per se.

FIG. 6 is a diagram of the hydraulic system.

FIGS. 7-10 are diagrammatic views illustrating different positions of the valve of said system.

FIG. 11 is an enlarged fragmentary sectional view showing the mounting for the intermediate wheel assemblies, taken substantially on the line 1111 of FIG. 2.

Referring to the drawings in detail, designated generally at 10 is the hollow, metal body of an earth compaction machine. Only the read end portion of said machine is illustrated, since the invention concerns itself only with the wheel mounting, that is, with the particular arrangement of the several pneumatic rollers or wheels relative to the body. In this connection, as will be noted from FIG. 2, there is illustrated only one transverse recess 12 of the body 10, in which recess a group of transversely spaced Wheels are mounted. It will be understood, however, that there could be a plurality of transverse rows of wheels, rather than the single row illustrated.

In any event, in the illustrated example the hollow body 10 has the downwardly opening recess 12, said recess extending across the full width of the body in the particular, illustrated example of the invention. The recess 12 in a commercial embodiment may quite likely be of arcuate formation, that is, the recess may have a side wall following the curvatures of the upper portions of the several wheels. In the illustrated example, the recess is generally rectangular, but regardless of the particular shape of the side wall of the recess, difiiculty has been previously experienced in that the wheels, when striking large obstructions that do not yield readily to compaction, and when passing over depressions will not compact at such points. This, of course, prevents efiicient operation of the machine.

In accordance with the present invention, means is provided that includes a hydraulic system adapted to provide a compact equalizing action that will permit the upward controlled vertical movement of the wheels under all kinds of road surface conditions.

Four wheels are shown in the group illustrated in FIG. 2, and it may be considered that the four wheel assemblies comprise two pairs of assemblies, the wheel assemblies of one pair being generally designated 14 and 15, and the wheel asesemblies of the other pair being generally designated 16 and 17. Assemblies 14 and 15 alternate with the assemblies 16 and 17, and the wheels of the assemblies 16 and 17 are spaced forwardly, that is, they are forwardly offset in respect to the wheel assemblies 14 and 15. In a commercial embodiment, the wheels of the assemblies 16 and 17 would likely be spaced forwardly from the wheels of the assemblies 14 and 15 a distance of about five inches, more or less. This is to provide axle clearance when one wheel is in a depression and the other on a high spot. The wheels are essentially in the same plane so far as the rolling action is concerned.

The wheel assemblies 14 and 17 are disposed on the outermost sides of the body of the machine as shown in FIG. 2. Each wheel assembly 14 and 17 includes a beam mounted for swinging movement upon a pair of rectangular, vertically elongated, transversely spaced support plates or brackets 18 fixedly secured to and projecting rearwardly from the front wall of recess 12. Each of said wheel assemblies 14 and 17 includes the transversely extending rotatable bearing sleeve 20, the opposite ends of which are disposed in close proximity to or in contact with the inner surfaces of the plates 18, and welded or otherwise fixedly secured to the sleeve 20 is an elongated, straight beam 22 disposed substantially horizontally when normally positioned, as shown in FIG. 1.

Beam 22 may be of various types of construction, but in the illustrated example is of box girder type (see FIGS. 3 and 4). In any event, beam 22 has one side surface in registration with one end of the sleeve 20, the other end of the sleeve projecting laterally beyond the other side surface of the beam, as will be clearly seen from FIG. 5.

It is preferred to reinforce the fixed connection between beam 22 and sleeve 2d. To this end, an obliquely disposed triangular upper gusset 24 is welded to the sleeve and to the top wall of the beam 22, while a triangular side gusset 26, also disposed obliquely to the length of the beam, is also fixedly connected between the sleeve 20 and to one side wall of the beam (see FIGS. 2 and 5).

The plates 18 are formed with openings aligned with the bore of sleeve 20, and extending through said openings and bore is a shaft 28, the opposite ends of which project beyond the respective plates 18 and are threaded. Washers 30 are applied to the projecting ends of the shaft, after which nuts 32 are threaded thereon to hold the shaft assembled with the plate.

This construction mounts the beams 22 for vertically swinging movement Within recess 12, about the axes defined by the transversely extending shafts 28.

Continuing with the description of the wheel assemblies 14 and 17, welded to opposite sides of the intermediate portion of each beam 22 and projecting upwardly from the beam is a pair of spindle support plates 34. Extend ing through the pair of plates 34 above beam 22, and welded to said plates 34 (see FIG. 4) is a sleeve 36, and extending through each sleeve is a stub axle 38, one end of which has a head 40 bearing against one of the plates 34. Axle 38 at its other end projects beyond the other plate 34, and has a threaded portion receiving a nut 42 which holds the axle against endwise movement within sleeve 36, in cooperation with the head 40.

The stubaxle 38 is formed with a reduced, axial extension 44, and a wheel has a disc 46 provided with a hub 48 into which extension 44 extends. Disc 46 has a rim 50 receiving a pneumatic tire 52. Holding the wheel on the extension 44 of the spindle is a nut, designated at 56 and engaging against a washer 54, nut 56 being mounted upon the threaded outer end portion of extension 44. The wheel on the axle 38 of wheel assembly 14 is indicated at 45, and the wheel on axle 38 of wheel assembly 17 is indicated at 80.

To the rear end of each beam 22 there is Welded a laterally projecting, triangular, channeled connecting bracket 58.

With reference to the wheel assemblies and 16, these assemblies are disposed inwardly of the wheel assemblies 14 and 17 and the mounting supports therefor are positioned between the assemblies 14 and 17 and are disposed in spaced superposed relationship, with the mounting support for wheel assembly 16 directly over the mounting support for the Wheel assembly 15, said supports being indicated generally at 65 and 67, respectively, in FIG. 11.

Each of the mounting supports 65 and 67 at one end includes pairs of projecting plates 60, similar to plates 18, Welded to the front wall of the recess 12 (FIG. 2). Each mounting support includes a sleeve 64 extending between respective pairs of plates and welded at its forward end to each sleeve 64 is a beam 66 of box girder construction.

Reinforcing the connection of each beam 66 to its sleeve 64 are gussets 68, 70. Gusset 70 is secured to the side wall of the beam 66, while gusset 68 is secured to the other side thereof as shown in FIG. 1. The gussets are obliquely disposed in respect to the length of the beam, in the same manner as the gussets 24, 26.

To the rear of each beam 66 there is welded or otherwise fixedly secured a laterally projecting, triangular, channelled bracket 72. The brackets are on opposite sides of the beams.

Welded to and extending upwardly from the opposite side walls of the beam 66 of the lower support 67 is a pair of axle supporting plates 74 having transversely aligned openings that are registered with the bores of a bearing sleeve 76 extending between and welded to said plates 74. Similarly a pair of axle supporting plates 74 is welded to the opposite side walls of the beam 66 of the upper support 65, which plates support a similar bearing sleeve 76 therebetween. In each of the bearing sleeves 76, a stub shaft 78, similar to stub shaft 38, is journalled, one shaft 78 extending laterally in one direction and supporting a wheel 53 and the other shaft 78 extending laterally in the opposite direction and supporting a wheel 81.

As will be noted, wheel 81 of wheel assembly 16 and wheel of wheel assembly 17 are offset in a direction forwardly from the wheels 45 and 53 of the assemblies 14 and 15, respectively, to a slight extent, in a preferred embodiment of the invention.

The hydraulic load-equalizing system comprises a plurality of hydraulic cylinder assemblies generally designated 82 associated with the wheel mounts. Each assembly is connected between the body 10 and the rear end of an associated beam 22 or 66 as the case may be. All the assemblies are identical, so the description of one will sulfice for all.

Referring to FIG. 3, each hydraulic assembly includes a cylindrical housing 84, in which is axially reciprocable a ram 86 that projects downwardly from the housing. Housing 84 at its upper end has an ear 87 disposed between brackets 90 rigid with the rear wall of the recess 12. A pivot pin 88 connects the ear 87 to and between the ears 90.

To the lower end of the ram 86 there is fixedly secured an ear 94 disposed between brackets 96 rigid with and extending upwardly from the lateral bracket 58 or 72 as the case may be, and a pivot pin 92 is extended through registered openings of the ear 94 and brackets 96 to pivotally connect the ram to the associated beam.

It will be understood that within the cylinders, the rams have pistons, illustrated diagrammatically at 97 in FIG. 6.

Extending into communication with the interior of the housings 84, above the pistons 97, are fluid pressure branch lines 98 of the wheel assemblies 15 and 17 and a line 99 of the assembly 16. Branch lines 98 are longer than the line 99, since their associated cylinder assemblies 82 are at a lower elevation than the cylinder assembly 82 associated with wheel assembly 16.

All the branch lines are connected to a main branch or manifold 100. A reservoir designated at 102 has a main supply line 104 extending therefrom, and a pump 106 is connected in the line 104, for pumping fluid under pressure from the reservoir 102 into the line for flow into the housings of the several hydraulic cylinder assemblies. Line 104 at its outlet end opens onto a threeway valve 108, and each branch line is equipped with a separate valve 105.

In order to load the system, valve 108 is moved to its FIG. 6 position and the pump 106 operated. Fluid will be pumped under pressure from the reservoir 102 into the line 100, flowing in opposite directions from the valve to all the cylinder assemblies 82.

Thereafter, if the valve 108 is moved to its FIG. 7 position the cylinder assemblies 82 of wheel assemblies 15 and 17 at one side of the valve structure are in communication with one another through line 100, and the same is true of the cylinders 82 of wheel assemblies 14 and 16 at the other side of the valve 108. However, the cylinder assemblies at one side of the valve are out of communication with the cylinder assemblies at the other side of the valve and the reservoir is cut off from communication with all the cylinder assemblies.

In these circumstances, if one wheel assembly is rocked upwardly or receives an impact tending to rock the same upwardly, the fluid in the cylinder assembly 82 associated therewith will tend to flow to the cylinder assembly 82 of the wheel assembly immediately adjacent thereto at the same side of the valve structure. An equalizing action is thus obtained, between the two wheel assemblies at one side of the longitudinal center line of the apparatus. It follows that there will be equalization of load, in the same fashion, between the two Wheel assemblies disposed at the other side of the longitudinal center line.

If the valve is placed in its FIG. 8 position, communication with the reservoir is prevented, so that there can be no back flow through the inoperative pump into the reservoir. Pressure is thus maintained in all the cylinder assemblies, just as it was in FIG. 7. However, in this arrangement, there is equalization among all four of the cylinder assemblies, since the line 100 extends continuously, without blockage, over its full length, communicating with all the cylinder assemblies.

In FIG. 9 is shown an arrangement wherein the pump is connected to the assemblies at one side of the longitudinal center line, for the purpose of permitting fluid to be pumped only to these assemblies. Alternatively, if the pump is not placed in operation, the arrangement shown in FIG. 9 will maintain fluid pressure within the cylinder assemblies that would be to the left of the valve viewing the same as in FIG. 9, while there would be a complete absence of pressure in the assemblies that would be on the right of the valve viewing the same as in FIG. 9.

In FIG. 10, a result opposite from that shown in FIG. 9 is obtained, that is, the reservoir is connected with the cylinder assemblies that are at the left of the valve, viewing the same as in FIG. 10.

Obviously, this provides for equalization of load, and permits the assemblies to be used either in pairs or as a complete group so far as said equalization is concerned. In every instance, any cylinder assembly can be maintained under a predetermined amount of pressure, in a manner such that when a wheel receives a blow tending to force the same upwardly, the blow will be equalized by the pressure fluid, and the force of the blow will be transmitted to one or more of the remaining wheel assemblies.

While I have illustrated and described the preferred embodiment of my invention, it is to be understood that I do not limit myself to the precise construction herein disclosed and that various changes and modifications may be made within the scope of the invention as defined in the appended claim.

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent is:

In a road Compactor, a body having spaced side walls and a recess rectangular in cross section and extending the width of the body, a plurality of spaced beams, rectangular in cross section, including two outer and two inner beams, each of said beams being pivoted at one end to one side wall of the recess, a plurality of shafts respectively journalled at one end midway of the ends of each of said beams and extending laterally thereof, a compactor wheel fixed to the laterally extending end of each of said shafts in said recess, hydraulic means reacting between the other end of the respective. beams and the other side wall of the recess to normally transmit to each beam a portion of the body weight to equalize the weight among the beams including cylinders to contain the liquid portion of said hydraulic means, rams having one end slidable in the cylinders and the other end connected to the beams, and means to place the cylinders for a plurality of said hydraulic means into open communication, the beams of the inner wheels being disposed in superposed relation in a vertical plane, with the ends of the wheel shafts there-between.

References Cited in the file of this patent UNITED STATES PATENTS 1,318,117 Stewart Oct. 7, 1919 2,270,390 Summers Jan. 20, 1942 2,706,121 Ronning Apr. 12', 1955 2,847,918 Harrison Aug. 19, 1958 FOREIGN PATENTS 1,153,038 France Sept. 16, 1957 

